Inconsistent Focus - Why?

[rvrkids]

Hello -
I have been practicing outdoor portraits and some of my shots have been great, but others are not as sharply focused as I would like.

I have an entry level dslr Nikon D50 and yesterday used the Nikon 50mm f/1.8. I have been shooting in either aperture priority or manual and have learned that wide open aperture can cause focus softening so I never went below 3.2.

I have attached 2 examples from yesterday. Both were raw exported from lightroom to jpg with no edits. Both were taken at f/3.5, ISO 200,1/60 shutter, 1/3 and 2/3 EV, center metering. One is great focus one is not...I can't tell in the soft one what is in focus if anything...I don't think it's a depth of field problem. This happens when my shutter speeds are faster too so I don't think it's a movement thing either.

Is there anything else that I could be doing wrong to cause the soft focus?

Also, all critiques of the photos are welcomed...good and bad

 

[Designer]

I tried to view the focus point, but there is no focus information in the EXIF. Did you focus manually?

So when you did the DOF calculations, what was the DOF?

If the point of focus was on her sleeve, for instance; and the DOF was about 8 inches in front of the sleeve, it is entirely possible that her eyes would not be within that 8 inches.

 

[KmH]

Which Nikon 50 mm f/1.8 do you have? There are 2 of them - the AF-D and the AF-G.

1/60 may not be a fast enough shutter speed to eliminate camera shake if your camera holding technique is less than exemplary.
The rule of thumb is 1/the lens focal length. 1/100 or even faster would have been better.
The total DoF in the second photo is deeper just because of the increase in point-of-focus distance.

The unmodified camera mounted flash is putting the pin light right in the center of her eyes. The 10:00 or 2:00 position from an off camera flash unit and a larger catch light and softer light a good sized light modifier - like a 30"+ umbrella - provides a much more pleasing look.

 

[rvrkids]

I tried to view the focus point, but there is no focus information in the EXIF. Did you focus manually?

So when you did the DOF calculations, what was the DOF?

If the point of focus was on her sleeve, for instance; and the DOF was about 8 inches in front of the sleeve, it is entirely possible that her eyes would not be within that 8 inches.

Thank you for your help. I used auto focus (my eyes are not the best anymore) and focused on her eyes and re-composed. But I did not use the center focus point, I used the one closest to her eyes so I barely had to move the camera to re-compose. I just now calculated the depth of field and it was probably somewhere in the range of 6".

When you lock the focus point, that holds the focus distance correct?? so if her eyes were say 7' from the focus point in my lens and then I recompose and that focus point is directed at her sleeve which is closer than 7' then probably nothing will be in focus if her eyes are more than 6" from her sleeve...is that right?

I really like bokeh but not at the cost of focus. If I calculated DOF for every shot it would take me forever....would I be better off just changing my aperture to a more "safe" setting??

I don't know why I am not capturing all of the metadata like focus information and I get very little flash data, only that it fired.

 

[rvrkids]

Which Nikon 50 mm f/1.8 do you have? There are 2 of them - the AF-D and the AF-G.

1/60 may not be a fast enough shutter speed to eliminate camera shake if your camera holding technique is less than exemplary.
The rule of thumb is 1/the lens focal length. 1/100 or even faster would have been better.
The total DoF in the second photo is deeper just because of the increase in point-of-focus distance.

The unmodified camera mounted flash is putting the pin light right in the center of her eyes. The 10:00 or 2:00 position from an off camera flash unit and a larger catch light and softer light a good sized light modifier - like a 30"+ umbrella - provides a much more pleasing look.

Thank you for your help. I have the AF-D. I guess I should always try to stay at 1/100 or faster just to be safe.

I see what you're saying about the pin light. Unfortunately I'm usually by myself and just picking random spots to take pictures (if I can get my daughter to agree to be my test model). I have the Nikon SB700 speed light. I did use the built in wide panel thinking it would make the light less harsh. Is there any other way to fix that using the flash on camera? Could I bounce it off of a the flash card mounted on top of the flash? I just don't know if that would work outside.

 

[KmH]

I really like bokeh but not at the cost of focus. If I calculated DOF for every shot it would take me forever..

You're talking about depth-of-field.
Bokeh is not adjustable and bokeh isn't a blurred background.
Bokeh is a subjective aesthetic quality of the blurred parts of a photo.
The most desirable quality of bokeh is that it be smooth - "cream cheese" smooth - and not look jittery, nervous, or like donuts.
In night shots that have bright lights in the background people strive for "Hollywood" bokeh or perfectly round blobs of out of focus lights.
Catadioptric mirror lenses deliver bokeh that looks like donuts because of the secondary mirror stuck in the center of the corrector plate at the front of the lens.

I don't calculate the DoF when I shoot, but I have a lot of experience and solid understanding of how to control the DoF.
As you get more experience you'll develop a better feel and understanding too.
DoF control is about more than the lens aperture, I think more about the point-of-focus distance than the lens aperture.

 

[paigew]

To me, it looks like missed focus...I'm on my phone but the bottom of her shirt looks sharp.


Sent from my iPhone using Tapatalk

 

[Designer]

I see what you're saying about the pin light. Unfortunately I'm usually by myself and just picking random spots to take pictures (if I can get my daughter to agree to be my test model). I have the Nikon SB700 speed light. I did use the built in wide panel thinking it would make the light less harsh. Is there any other way to fix that using the flash on camera? Could I bounce it off of a the flash card mounted on top of the flash? I just don't know if that would work outside.

Your flash can put out a surprising amount of light. The smallish diffusers and reflectors that are built into the flash head are still not large enough to produce the soft light that will enhance your model's features.

Now if you had say, someone else who could hold a large white reflector you could bounce the flash off that. Sometimes even somebody's white shirt will reflect some nice light and being kind of large, will diffuse the light.

Better yet would be someone holding one of those 42-inch diameter reflectors and holding it just right to reflect light under the chin and into the eye sockets. Or your third hand holding it at just the right angle while your other two hands take the picture.

 

[astroNikon]

When you move the camera to recompose,
be aware that the DOF is based on when you took & locked focus
not on where you "moved" to
So if you move forward or back then your DOF position has changed

If you focus seems to be on something else and your position doesn't really move, also make sure that you are locking focus before and after you recompose your shot.

 

[Derrel]

Both those shots are slightly back-focused, meaning the point of best focus is behind her face. That can happen pretty easily. As closer distances like this, depth of field is very minimal at apertures like f/3.2. To ENSURE that you'll get a good, sharp person, face sharp and body sharp, the lens needs to be stopped down to a safer aperture, like f/8. Again, you were CLOSE to her, and at close ranges, depth of field is very shallow. Focus and re-compose works well at distances beyond about 15 feet, and with most shorter lenses, there will not be a problem with it. But, when you are physically close, and you focus and recompose using the center AF square, at wider f/stops like f/3.2, it's possible that the depth of field will not be deep enough to "cover" the difference in distance, or slight subject movement, or slight focusing errors, or a combination of those things. Again, at close ranges, focusing becomes SUPER-CRITICAL! Even slight mistakes, slight inaccuracies, slight back-focusing or front-focusing tendencies the lens has on that specific body, or slight mis-aiming of the focusing bracket, anything like that, can cause a focusing error. The subject might very well lean forward or back a few inches, or you might, or both of you might, or you might find yourself ever-so-slightly leaning forward as you look through he camera while composing.

Again, I say that "you might find yourself ever-so-slightly leaning forward as you look through he camera while composing,": because I see people doing that all the time. It seems to me to be a subconscious thing, but a lot of people do this. I think it's an effort to mentally "connect" more with the subject.

 

[bratkinson]

As Derrel and others have indicated, focus-and-recompose technique, DOF, and shutter speed issues all might be contributing factors less than sharp photos. And, as the OP stated, as no editing was done in Lightroom, a little bit of sharpening will go a long way in fixing the tad-soft issue.

I'm just an amateur 'hack' photographer, and at my Social Security age, trying to remember a lot of numbers like DOF is this when aperture is that and distance is such-and-such is not an option, especially since my memory is 'going fast' these days. So I've learned to think in terms of 'more/less DOF', 'more/less aperture', and 'more/less shutter speed' to get the shots I want. As I do much of my work in low light, indoor events, I'm usually shooting at or near wide open with fast lenses, so other than shutter speed necessary to freeze subject movement (and mine), DOF is my biggest concern...do I want more or less?

I'm sort of 'on automatic' in knowing that regardless of the lens, the closer one gets to the subject, the less DOF there is, sometimes less than an inch! So, unless I really WANT a thin DOF (or am forced to by exposure triangle requirements), I'll shoot at f5.6 or something close. For group shots, f8 or better. I also limit my focus and recompose shots and when I do, always f5.6 or better, to ensure everything I want is in focus. And when I really want a super-thin DOF, no focus and recompose, and center AF point right where I want it to be, on the subjects' left eye. Why the left eye? I haven't a clue as why that's my choice...maybe it's because I'm left handed. Remembering that lenses aren't their sharpest wide open, I'm usually stopped down just a bit from wide open for my thin DOF shots as well.

Bottom line...practice, practice, practice. As "they" always say...experience is the best teacher.

 

[chainsawal]

To me, it looks like missed focus...I'm on my phone but the bottom of her shirt looks sharp.


Sent from my iPhone using Tapatalk

Same here... I zoomed in to the bottom of her shirt on the 2nd picture where her eyes are out of focus.. and the bottom of that shirt is very sharp... and it looks like the shirt is about 6" behind her face (although hard to tell from a 2d picture). Photo appears to be back focused about 4-8" like others said.

I think one mistake a lot of beginning photographer make (and I did as well) is you think to get that beautiful Bokeh that you have to use the lowest f-stop the lens offers... without regard to distance and DOF as others have pointed out.

The best learning tool for me was my 105mm f/2.8 MACRO (or any good macro).... as that really compounds DOF issues shooting macro... you can literally have an insect's eyes in focus and his body out of focus within a couple of millimeters as the DOF is razor thin as you go wide open.

 

[rvrkids]

Thank you everyone for your responses. I have been reading and learning about things that affect dof and have learned a lot this week!

Now I have another question I will be posting

 

[The_Traveler]

When you calculate DOF (on DOFmaster.com) you need to remember that half of that DOF is in front of your focus point and half behind, if you are off a bit, it is quite easy for the tip of her nose to be OOF when you shoot at f3.2.
If you shoot at f8, the DOF is only about a foot so you'll get the OOF blur you'll like anyway.
Toss that first one. She looks startled and her chest is wayyyy too prominent.
The second one is much nicer.